question/advice

I am in my early twenties and TTC. I have had an ultrasound to make sure there is nothing blocking my uterus, nothing was found, I have done ovulation tests and they come back positive, and my period comes every month like clock work. yet I can not conceive. when I have sex and my hubby cums it all runs down my leg even if I lay in bed for an hour afterwards. is it me? is there something happening I don't know about and the Dr missed it? can anyone share a few words of wisdom?